Door lock



Nov. 3, 1970 A. H. LIPPMAN 3,537,739

DOOR LOCK Filed Feb. 19, 1969 INVENTOR. AARON HARRY LIPPMAN FIG. 4

ATTORNEY United States Patent Oflice DOOR LOCK Aaron Harry Lippman, Rochester, N.Y., assignor to Brainerd Manufacturing Co., Inc., East Rochester, N.Y.,

a corporation of New York Filed Feb. 19, 1969, Ser. No. 800,457 Int. Cl. Ec 19/06 US Cl. 292-2 Claims ABSTRACT OF THE DISCLOSURE A door lock is made with a slotted guide plate, a post extending through the slot, a retainer holding the post in place, a spring-loaded knob wider than the slot and movable axially on the post, and the slot having an enlarged end near the door so that the knob snaps into the slot enlargement to latch relative to the guide plate. to block the opening of the door. By pulling the knob out of the slot enlargement and sliding it along the slot out of the way of the door, the door can be opened.

BACKGROUND OF THE INVENTION Many door locks have been proposed for blocking the opening of a door from the inside. To be successful, these must be intruder proof, attractive, simple, economical and easy to install and operate. The invention presents an optimum solution for such door locks.

A slotted guide plate is mounted on the door frame adjacent the closing edge of the door, and the slot in the plate extends away from the closing edge of the door. A door blocking member follows the slot for moving toward and away from the closing edge of the door, and the door blocking member latches into the guide plate in a lock position. The door blocking member includes a post extending through the slot and attached to a retainer, a hollow knob slidable on the post toward and away from the plate, and a compression spring between a cap on the post and the bottom of the hollow knob for biasing the knob toward the plate. The end of the slot closest to the door is enlarged to receive part of the knob for the latching engagement with the plate, and in such position, the door blocking member prevents opening of the door. By compressing the spring and moving the knob out of the slot enlargement and along the slot away from the door, the door is freed for opening again.

DRAWINGS FIG. 1 is a partially sectioned, plan view of a preferred embodiment of the inventive door lock mounted in lock position;

FIG. 2 shows the door lock of FIG. 1 moved aside to allow opening of the door;

FIG. 3 is a cross section through the door blocking member taken along the line 3-3 of FIG. 1;

FIG. 4 is a side elevation of the invention door lock in the position illustrated in FIG. 2.

DETAILED DESCRIPTION One preferred embodiment of the inventive door lock is shown in the drawings for convenience of illustration, but many other door locks can follow the spirit of the invention and still use different guide plates, blocking members, or slot and knob arrangements for moving the door blocking member into a latched engagement with the guide plate to lock a door.

As shown in the drawings, guide plate 10 is secured to door frame 11 by screws 12 adjacent the closing edge 13 of door 14. A blocking member 15 is arranged for travelling in closed slot 16 in plate 10 for locking or unlocking 3,537,739 Patented Nov. 3, 1970 door 14. Plate 10 has a curve 17 and slot 16 extends around curve 17 so that blocking member 15 can be moved between the lock position shown in FIG. 1 and the unlocked position shown in FIG. 2. Location marks 18 are preferably embossed on plate 10 for properly locating plate 10 on door frame 11.

Door blocking member 15 includes a post 20 that is preferably square and shaped to fit in closed slot 16 for sliding smoothly along the length of slot 16. One end of post 20 is secured to a retainer 21, preferably in the form of a curved washer held on post 20 by riveting over the end of post 20. Retainer washer 21 is wider than slot 16 and rides along the back surface of plate 10. The curvature of washer 21 helps it glide smoothly around curve 17 in plate 10, The other end of post 20- has an enlarged cap 22.

A hollow knob 23 fits on post 20 for sliding axially on post 20 toward and away from plate 10. A compression spring 24 between the bottom of hollow knob 23 and the underside of cap 22 biases knob 23 toward plate 10. The plate end of knob 23 is wider than slot 16 and preferably formed as a cross bar 25 transverse to slot 16. Glide buttons 26 are fitted in recesses in cross bar 25 for bearing against the face of plate 10* for a smooth and relatively friction-free gliding of knob 23 along plate 10. Glide buttons 26 are preferably formed of nylon or other relatively low-friction plastic material. A radially enlarged rim 27 on knob 23 provides a finger-grip surface for moving knob 23 away from plate 10 toward cap 22. Flat face 28 on knob 23 faces door 14 to provide a flat, door-engaging surface.

The end of slot 16 nearest to door 14 is enlarged, preferably by cross slot 30, configured for receiving cross bar 25 on knob 23. Bevels 31 are preferably formed on the corners between slot 16 and cross slot 30 to help guide post 20 into slot 16.

When door-blocking member 15 is moved along slot 16 from the position illustrated in FIG. 2, around curve 17, and to the position illustrated in FIG. 1, across bar 15 snaps into cross slot 30 under the bias of compression spring 24. The engagement between cross bar 25 and cross slot 30 aifords a secure latch between blocking member 15 and plate 10. With blocking member 15 in such position, door '14 is confronted by flat face 28 and cannot be opened.

To unlock door 14, knob 23 is gripped around rim 27 and pulled away from plate 10 to compress spring 24 sufficiently to draw cross bar 25 out of cross slot 30. Then knob 23 is moved away from door 14 along slot 16 with glide buttons 26 riding against the face of plate 10 on opposite sides of slot 16. Blocking member 15 is moved far enough along slot 16 to round the curve 17 and rest at the end of slot 16 in the position shown in FIG. 2. This removes blocking member 15 from the path of door 14 and allows door 14 to open as shown in FIG. 2.

Persons wishing to practice the invention should remember that other embodiments and variations can be adapted to particular circumstances. Even though one point of view is necessarily chosen in describing and claiming the invention, this should not inhibit broader or related applications within the spirit of the invention. For example, the guide plate can have many difierent shapes and mountings, other blocking members can be used, and a guide slot can be shaped in many ways to provide a latching fit between the knob and the slot.

I claim:

1. A door lock comprising:

(a) a guide plate mounted in the region of the opening edge of said door;

(b) said guide plate having a closed slot extending away from said closing edge of said door;

(c) a door-blocking member arranged to follow said slot in moving toward and away from said closing edge of said door;

(d) said door-blocking member comprising:

(1) a post extending through said slot;

(2) said post fitting said slot;

(3) one end of said post being secured to a retainer larger than said slot;

(4) said retainer engaging a surface of said plate;

(5) the other end of said post having a cap spaced from said plate;

(6) a hollow knob on said post between said plate and said cap;

(7) said knob fitting said post for sliding on said post toward and away from said plate;

(8) the plate end of said knob being wider than said slot; and

(9) a compression spring on said post between said cap and said plate end of said knob;

(e) the end of said slot nearest said closing edge of said door being enlarged to receive a portion of said knob in latching engagement with said plate under the bias of said spring.

2. The door lock of claim 1 wherein said plate has a curved portion turning away from said closing edge of said door, and said slot extends around said curved portion.

3. The door lock of claim 2 wherein said knob in said latching engagement with said plate is disposed to block opening of said door.

4. The door lock of claim 3 wherein said retainer is a washer having a curved surface engaging said plate to follow the inside of said curved portion.

5. The door lock of claim 1 including a pair of glide 4 buttons in said plate end of said knob for gliding against said plate on oppositesides of said slot.

6. The door lock of claim 1 wherein said plate end of said knob includes a cross bar transverse to said slot and fitting into said slot enlargement.

7. The door lock of claim 6 including a pair of glide buttons in said cross bar for gliding against said plate on opposite sides of said slot.

8. The door lock of claim 7 wherein said plate has a curved portion turning away from said closing edge of said door, and said slot extends around said curved portion.

9. The door lock of claim 8 wherein said knob in said latching engagement with said plate is disposed to block opening of said door.

10. The door lock of claim 3 wherein said retainer is a washer having a curved surface engaging said plate to follow the inside of said curved portion.

References Cited UNITED STATES PATENTS 614,052 11/1898 Jackson 292-295 766,357 8/1904 Ives 2922 792,966 6/1905 Coleman et al. 29.2-296 1,266,689 5/1918 Kinghorn 292295 3,432,199 3/1969 Sorrell 292-292 MARVIN A. CHAMPION, Primary Examiner R. L, WOLFE, Assistant Examiner US. Cl. X.R. 

